The present invention relates generally to a mixer valve for a faucet incorporating a movable valve element housed in a cartridge and more particularly to a ball valve element housed in a cartridge.
Widespread consumer acceptance has been given to single handle faucets, as shown in U.S. Pat. No. 3,056,418, that control both hot and cold water flow. These faucets are commonly constructed so that a handle or knob is movable in two distinct directions to adjust the mix of hot and cold water and to adjust the volume or flow rate.
Various challenges exist with a ball valve construction. In particular, the ball valve element is mounted between elastomeric inlet seals positioned about the inlet ports of the valve body and a sealing gasket that is mounted under the valve cover. The elastomeric inlet seals and gasket are all yielding and render a floating characteristic to the ball valve element between the valve body and cap. There is no positive lock or locator mechanism that securely positions the ball valve in place. Because the ball valve can be moved in a translational manner against the elastomeric elements, the operator when operating the handle can also move the handle a small amount in any direction including directions not contemplated in the design of the mixing valve. This unwanted motion renders an undesirable spongy feel to the operation of the faucet and an uncertainty to the operator as to the proper operation of the faucet. Furthermore, the spongy feel of the handle gives the impression that the handle is unstable and not assembled properly.
The top sealing gasket provides three functions. Firstly, it seals against leakage of water about the ball. Secondly, its outer periphery seals against the inner surface of the housing to prevent leakage. Thirdly, the gasket resiliently positions the ball downwardly against the inlet seals. As a consequence, the gasket is an expensive component due to its mass and shape. To obtain a smooth operation, the elastomeric sealing gasket often has a thin layer of tetraflouroethylene that contacts the ball valve to reduce wear as compared to direct contact of the elastomeric material with the ball member.
In order to reduce the floating feel, a regulation ring has been incorporated in many ball valve mixing valves. The regulation ring is adjustably screwed into the valve cap. The regulation ring pushes the sealing gasket downward against the ball valve element which in turn is pressed against the inlet seals. The downward placement of the sealing gasket and ball valve element reduces the undesirable motion but does not eliminate it. Furthermore, the combining of the regulation ring with the known gasket increases the cost and complexity of the mixing valve. The increased pressure exerted in the sealing gasket wears down the gasket. As wear and tear progresses, the regulation ring must be repeatedly adjusted to restore pressure on the gasket to both seal and provide the handle with an operating resistance that maintains it in a stable position against gravitational and other forces exerted on a faucet handle.
Heretofore, ball valves have not been amenable to a cartridge construction. Firstly, the floating nature of the traditional ball valve demanded that any cartridge completely surround and capture the ball valve, otherwise the ball valve simply falls out of the bottom of the cartridge. Secondly, the compact nature of the ball valve construction leaves little room for the inclusion of a cartridge. The introduction of traditional cartridges that house and capture the ball into the faucet housing demands that the housing be made taller to incorporate the added height needed for the inclusion of the cartridge.